STORMWATER CLIMATE RESILIENCE

Transcription

1 STORMWATER CLIMATE RESILIENCE NEWEA ANNUAL CONFERENCE JANUARY 22, 2018 BOSTON, MASSACHUSETTS STEVEN P. ROY TRINE STAUSGAARD MUNK RAMBOLL LIVEABLE CITIES LAB CLIMATE ADAPTATION & GREEN INFRASTRUCTURE 22/01/2018

2 22/01/2018

3 COPENHAGEN HARBOUR BEFORE (CIRCA 1995) 2 WWTPs CSO s Hydraulic modelling and real-time management controls Goal of 1 in 100 CSO event

4 COPENHAGEN HARBOUR - AFTER (2014) CLEAN WATER AND NEW RECREATIONAL USE

5 COPENHAGEN HAS ALSO BEEN FACING CHALLENGES DUE TO CLIMATE CHANGE

6 EXTREME CLOUDBURSTS IN 2010 AND Copenhagen was hit by the worst and most destructive cloudburst in the city s history Damages caused by floods: 6 billion DKK (~1 billion USD) 6.9 inches of rain in 2 hours

7 EXTREME CLOUDBURSTS IN 2010 AND INCHES FELL IN 2 HOURS Major economic losses due to closed transportation, limited mobility, and business closures in addition to direct flood damages

8 COPENHAGEN CASE DRIVERS AND PROCESS Climate plan KK, 2009 Extreme cloudburst 15 August 2010 Climate adaptation plan, 2011 Extreme cloudbursts 2 July and 15 August 2011 Cloudburst Masterplan, Specific projects >

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13 INCREASE IN EXTREME PRECIPITATION EVENTS FM Global Coping With Extremes, 2016 Increasing frequency of extreme precipitation events is a major risk facing US businesses Source: Climate Change Impacts in the US: The Third National Climate Assessment, 2014

14 NYC PRECIPITATION PROJECTIONS Source: NYC Panel on Climate Change, 2015

15 NYC CLIMATE PROJECTIONS HEAT Source: NYC Panel on Climate Change, 2015

16 CLIMATE PROJECTIONS SEA LEVEL RISE Source: NYC Panel on Climate Change, 2015

17 NEW YORK CITY SE QUEENS CLOUDBURST/CLIMATE RESILIENCE PILOT 22/01/2018

18 NYC CLIMATE RESILIENCY STUDY

19 NYC CLIMATE RESILIENCY STUDY Deliverables Key concepts Integrated planning Liveability Blue-Green Infrastructure (BGI)

20 NYC CLIMATE RESILIENCY STUDY 4-step approach to cloudburst resiliency planning An iterative process Cost analysis vs. Cost-Benefit Analysis

21 NYC CLIMATE RESILIENCY STUDY Designing a masterplan BGI Elements

22 NYC CLIMATE RESILIENCY STUDY BGI Examples Cloudburst Road (Skt. Annæ Plads) Retention Street (Kong Hans Allé) Central Retention (Tanner Springs Park) Local Retention (Freiburg Zollhallenplatz)

23 NYC CLIMATE RESILIENCY STUDY SE QUEENS Study area 3,200 Acres 110,000 residents Dominated by fences Low to middle income families

24 NYC CLIMATE RESILIENCY STUDY

25 NYC CLIMATE RESILIENCY STUDY

26 NYC CLIMATE RESILIENCY STUDY

27 NYC CLIMATE RESILIENCY STUDY Workshops Local knowledge Ownership (be part of the evolution )

28 NYC CLIMATE RESILIENCY STUDY Initial analysis Land-use data Terrain Infrastructure (transport and social) Green areas etc. Workshop I Supplement with local knowledge Identify challenges and opportunities

29 NYC CLIMATE RESILIENCY STUDY Detailed analysis Flood modelling GIS analysis Risk mapping Masterplan drafts Workshop II Supplement with local knowledge Identify challenges and opportunities

30 NYC CLIMATE RESILIENCY STUDY Final cohesion Final masterplan Final pilot projects Workshop III Strategic planning exercise Next steps Evaluation

31 NYC CLIMATE RESILIENCY STUDY Masterplan (68 projects) 11 cloudburst roads 16 cloudburst roads with retention 15 retention streets 4 cloudburst pipes 18 central retention 4 local retention

32 NYC CLIMATE RESILIENCY STUDY Considerable less flooding Considerable lower damage costs

33 NYC CLIMATE RESILIENCY STUDY Capital investment: $330 million Avoided risk costs: $310 million Net loss: $-20 million

34 NYC CLIMATE RESILIENCY STUDY CBA Aesthetic values Air quality Health benefits Etc. Avoided social and environ. costs: $290 million Created social and environ. Values: $3 million

35 NYC CLIMATE RESILIENCY STUDY Pilot project: Conceptual cloudburst road

36 NYC CLIMATE RESILIENCY STUDY Pilot project: South Jamaica Houses

37 NYC CLIMATE RESILIENCY STUDY

38 NYC CLIMATE RESILIENCY STUDY Challenges Changing the Level of Service Bringing agencies together Data protection (reluctant to share) Political concerns Stakeholder involvement

39 BUZZARDS POINT, WASHINGTON D.C. BACKGROUND FOR PROJECT A comprehensive climate resilience plan and design Includes flood mitigation vision, but no measures Portions of Buzzard Point are identified as a highrisk flood zone in the effective Flood Insurance Rate Map (FIRM) Current District regulations require that the lowest floors of residential structures be 1.5 feet above the 100-year flood elevation Vision to maintain first floor elevations above the level of the 500-year flood event for residential buildings 22/01/2018

40 Existing Proposals 3 Developments along the water edge : Riverpoint Peninsula Half Riverpoint 22/01/2018

41 BACKGROUND FOR PROJECT Lack of overall plan for development and resilience for area Need for validation or new recommendation of acceptance criteria related to flood protection A proposal to raise the streets as flood mitigation strategy is the only suggestion at present this proposal is not analyzed in depth: - Is it resilient, flexible and robust against climate change and extreme events - How does raised streets impact the urban plan, architecture, accessibility etc. - Is it the most cost-efficient way and who pays for construction and operation? 22/01/2018

42 MODELLING APPROACH MIKE FLOOD: MIKE Urban connected to MIKE 21 MIKE Urban hydrological and hydraulic model MIKE 21 2D overland model

43 EXAMPLE OF FLOOD SIMULATION OF A FLUVIAL AND TIDAL STORM SURGE EVENT

44 POTENTIAL OF IMPROVEMENTS Detail the sewer system to include smaller sewer pipes and thus get more detailed results Divide the catchments into the actual catchment of each manhole to the more accurate distribution of water Find the whole catchment area of the pumping station to simulate the correct boundary conditions Find the exact pumping capacity in order to simulate when the capacity of the pumping station is exceeded Perform simulations with proposed cloud burst solutions (cloud burst roads, channels, retention ponds etc.)

45 FLOOD ANALYSIS SCENARIOS Cloudburst 1/10 year today 1/100 year today Fluvial and tidal storm surges 1/100 year today 1/500 year today* 1/1000 year today* * expert judgement, outside statistics Existing conditions, proposed development and alternative plan.

46 100 YEAR EVENT IN 2017 UNDER EXISTING CONDITIONS

47 100 YEAR EVENT IN 2100 UNDER EXISTING CONDITIONS

48 100 YEAR EVENT IN 2017 UNDER EXISTING CONDITIONS

49 100 YEAR EVENT IN 2100 WITH CURRENT PROPOSAL

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51 VISION PLAN, REVISED

52 Keep Drainage Systems Reasonable and Cost-effective REDUCING INFRASTRUCTURE COSTS AND INCORPORATING CLIMATE RESILIENCY WITH BLUE-GREEN SOLUTIONS 1 year 3 years 5-10 years years Combined blue green solutions 10 years Effect of combined Blue Green solutions with conventional (grey) pipes

53 THANK YOU Steven Roy Tel: